U.S. patent number 10,968,777 [Application Number 16/393,205] was granted by the patent office on 2021-04-06 for chordal seal.
This patent grant is currently assigned to RAYTHEON TECHNOLOGIES CORPORATION. The grantee listed for this patent is United Technologies Corporation. Invention is credited to Kyle J. Brevick, Tracy A. Propheter-Hinckley.
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United States Patent |
10,968,777 |
Propheter-Hinckley , et
al. |
April 6, 2021 |
Chordal seal
Abstract
A vane for a gas turbine engine includes at least one airfoil. A
first platform has a first rail located at a first end of the
airfoil. A second platform has a second rail located at a second
end of the airfoil. A first chordal seal is located on an axially
aft surface of the first rail. A second chordal seal is located on
an aft surface of the second rail and has a second radius of
curvature at least partially truncated by an outer edge of the
second rail.
Inventors: |
Propheter-Hinckley; Tracy A.
(Rocky Hill, CT), Brevick; Kyle J. (Windsor, CT) |
Applicant: |
Name |
City |
State |
Country |
Type |
United Technologies Corporation |
Farmington |
CT |
US |
|
|
Assignee: |
RAYTHEON TECHNOLOGIES
CORPORATION (Farmington, CT)
|
Family
ID: |
1000005468887 |
Appl.
No.: |
16/393,205 |
Filed: |
April 24, 2019 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200340405 A1 |
Oct 29, 2020 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01D
25/246 (20130101); F01D 11/005 (20130101); F01D
9/041 (20130101); F05D 2220/32 (20130101); F05D
2240/12 (20130101); F05D 2240/55 (20130101); F01D
9/04 (20130101); F01D 9/00 (20130101); F01D
9/02 (20130101) |
Current International
Class: |
F01D
25/24 (20060101); F01D 11/00 (20060101); F01D
9/04 (20060101); F01D 9/00 (20060101); F01D
9/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3043361 |
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Jul 2016 |
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EP |
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3054099 |
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Aug 2016 |
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EP |
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3054099 |
|
Nov 2016 |
|
EP |
|
3093445 |
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Nov 2016 |
|
EP |
|
3054099 |
|
Aug 2017 |
|
EP |
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3244019 |
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Nov 2017 |
|
EP |
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3244019 |
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May 2020 |
|
EP |
|
Other References
EP Extended Search Report for EP Application No. 20169273.8 dated
Sep. 3, 2020. cited by applicant.
|
Primary Examiner: Nguyen; Ninh H.
Assistant Examiner: Delrue; Brian Christopher
Attorney, Agent or Firm: Carlson, Gaskey & Olds,
P.C.
Claims
What is claimed is:
1. A vane for a gas turbine engine comprising; at least one
airfoil; a first platform having a first rail located at a first
end of the airfoil; a second platform having a second rail located
at a second end of the airfoil; a first chordal seal located on an
axially aft surface of the first rail; and a second chordal seal
located on an axially aft surface of the second rail having a
second radius of curvature at least partially truncated by an outer
edge of the second rail; wherein the first rail includes a radially
outermost edge extending along a curvature, a first plateau on the
axially aft surface that is located radially outward from the first
chordal seal with the first plateau extending between a first
circumferential edge and a second circumferential edge, and the
first chordal seal includes a first radius of curvature and the
first and second chordal seal extend in a linear direction.
2. The vane of claim 1, wherein the outer edge of the second rail
that at least partially truncated the second chordal seal is a
radially inner edge of the second rail.
3. The vane of claim 2, wherein the radially inner edge at least
partially defines a radially innermost surface on the second
rail.
4. The vane of claim 1, wherein the first rail includes a second
plateau on the axially aft surface located radially inward from the
first chordal seal with the second plateau extending between the
first circumferential edge and second circumferential edge, and the
first plateau is axially offset from the second plateau.
5. The vane of claim 4, wherein a radially outer edge of the first
chordal seal is connected with the first plateau by a first fillet
and a radially inner edge of the first chordal seal is connected
with the second plateau by a second fillet.
6. The vane of claim 2, wherein the second rail includes a first
plateau on the axially aft surface of the second rail located
radially outward from the second chordal seal.
7. The vane of claim 6, wherein a radially inner edge of the second
chordal seal at least partially defines a radially inner edge of
the second rail.
8. The vane of claim 1, wherein a downstream most point on the
first chordal seal is located axially aft of a downstream most
point on the second chordal seal.
9. The vane of claim 1, wherein the first radius of curvature is
equal to the second radius of curvature.
10. A gas turbine engine comprising: a compressor section upstream
of a combustor section; a turbine section located downstream of the
combustor section, and at least one of the turbine section or the
compressor section includes a vane having: at least one airfoil a
first platform having a first rail located at a first end of the
airfoil; a second platform having a second rail located at a second
end of the airfoil; a first chordal seal located on an axially aft
surface of the first rail; and a second chordal seal located on an
axially aft surface of the second rail having a second radius of
curvature at least partially truncated by an outer edge of the
second rail; wherein the first rail includes a radially outermost
edge extending along a curvature, a first plateau on the axially
aft surface that is located radially outward from the first chordal
seal with the first plateau extending between a first
circumferential edge and a second circumferential edge of the first
rail and the first chordal seal includes a first radius of
curvature and the first chordal seal engages a blade outer air
seal.
11. The gas turbine engine of claim 10, wherein the outer edge of
the second rail that at least partially truncated the second
chordal seal is a radially inner edge of the second rail and the
first chordal seal and the second chordal seal extend in a linear
direction.
12. The gas turbine engine of claim 11, wherein the radially inner
edge at least partially defines a radially innermost surface on the
second rail.
13. The gas turbine engine of claim 10, wherein the first rail
includes a second plateau on the axially aft surface located
radially inward from the first chordal seal with the second plateau
extending between the first circumferential edge of the first rail
and the second circumferential edge of the first rail and the first
plateau is axially offset from the second plateau.
14. The gas turbine engine of claim 13, wherein a radially outer
edge of the first chordal seal is connected with the first plateau
by a first fillet and a radially inner edge of the first chordal
seal is connected with the second plateau by a second fillet.
15. The gas turbine engine of claim 10, wherein the second rail
includes a first plateau on the axially aft surface of the second
rail located radially outward from the second chordal seal.
16. The gas turbine engine of claim 15, wherein a radially inner
edge of the second chordal seal at least partially defines a
radially inner edge of the second rail.
17. The gas turbine engine of claim 10, wherein a downstream most
point on the first chordal seal is located axially aft of a
downstream most point on the second chordal seal.
18. The gas turbine engine of claim 10, wherein the first radius of
curvature is equal to the second radius of curvature.
Description
BACKGROUND
A gas turbine engine typically includes a fan section, a compressor
section, a combustor section, and a turbine section. Air entering
the compressor section is compressed and delivered into the
combustion section where it is mixed with fuel and ignited to
generate a high-speed exhaust gas flow. The high-speed exhaust gas
flow expands through the turbine section to drive the compressor
and the fan section.
Gas turbine stator vane assemblies typically include a plurality of
vane segments which collectively form the annular vane assembly.
Each vane segment includes one or more airfoils extending between
an outer platform and an inner platform. The inner and outer
platforms collectively provide radial boundaries to guide core gas
flow past the airfoils. Core gas flow may be defined as gas exiting
the compressor passing directly through the combustor and entering
the turbine.
Vane support rings support and position each vane segment radially
inside of the engine diffuser case. In most instances, cooling air
bled off of the fan is directed into an annular region between the
diffuser case and an outer case, and a percentage of compressor air
is directed in the annular region between the outer platforms and
the diffuser case, and the annular region radially inside of the
inner platforms.
The fan air is at a lower temperature than the compressor air, and
consequently cools the diffuser case and the compressor air
enclosed therein. The compressor air is at a higher pressure and
lower temperature than the core gas flow which passes on to the
turbine. The higher pressure compressor air prevents the hot core
gas flow from escaping the core gas flow path between the
platforms. The lower temperature of the compressor flow keeps the
annular regions radially inside and outside of the vane segments
cool relative to the core gas flow.
SUMMARY
In one exemplary embodiment, a vane for a gas turbine engine
includes at least one airfoil. A first platform has a first rail
located at a first end of the airfoil. A second platform has a
second rail located at a second end of the airfoil. A first chordal
seal is located on an axially aft surface of the first rail. A
second chordal seal is located on an aft surface of the second rail
and has a second radius of curvature at least partially truncated
by an outer edge of the second rail.
In a further embodiment of any of the above, the outer edge of the
second rail that at least partially truncated the second chordal
seal is a radially inner edge of the second rail.
In a further embodiment of any of the above, the radially inner
edge at least partially defines a radially innermost surface on the
second rail.
In a further embodiment of any of the above, the first rail
includes a first plateau on the axially aft surface that is located
radially outward from the first chordal seal. The first chordal
seal includes a first radius of curvature.
In a further embodiment of any of the above, the first rail
includes a second plateau on the axially aft surface located
radially inward from the first chordal seal. The first plateau is
axially offset from the second plateau.
In a further embodiment of any of the above, a radially outer edge
of the first chordal seal is connected with the first plateau by a
first fillet. A radially inner edge of the first chordal seal is
connected with the second plateau by a second fillet.
In a further embodiment of any of the above, the second rail
includes a first plateau on the axially aft surface of the second
rail located radially outward from the second chordal seal.
In a further embodiment of any of the above, a radially inner edge
of the second chordal seal at least partially defines a radially
inner edge of the second rail.
In a further embodiment of any of the above, a downstream most
point on the first chordal seal is located axially aft of a
downstream most point on the second chordal seal.
In a further embodiment of any of the above, the first radius of
curvature is equal to the second radius of curvature.
In another exemplary embodiment, a gas turbine engine includes a
compressor section upstream of a combustor section. A turbine
section is located downstream of the combustor section. At least
one of the turbine section or the compressor section includes a
vane that has at least one airfoil. A first platform has a first
rail located at a first end of the airfoil. A second platform has a
second rail located at a second end of the airfoil. A first chordal
seal is located on an axially aft surface of the first rail. A
second chordal seal is located on an aft surface of the second rail
and has a second radius of curvature at least partially truncated
by an outer edge of the second rail.
In a further embodiment of any of the above, the outer edge of the
second rail that at least partially truncated the second chordal
seal is a radially inner edge of the second rail.
In a further embodiment of any of the above, the radially inner
edge at least partially defines a radially innermost surface on the
second rail.
In a further embodiment of any of the above, the first rail
includes a first plateau on the axially aft surface located
radially outward from the first chordal seal. The first chordal
seal includes a first radius of curvature.
In a further embodiment of any of the above, the first rail
includes a second plateau on the axially aft surface located
radially inward from the first chordal seal. The first plateau is
axially offset from the second plateau.
In a further embodiment of any of the above, a radially outer edge
of the first chordal seal is connected with the first plateau by a
first fillet. A radially inner edge of the first chordal seal is
connected with the second plateau by a second fillet.
In a further embodiment of any of the above, the second rail
includes a first plateau on the axially aft surface of the second
rail located radially outward from the second chordal seal.
In a further embodiment of any of the above, a radially inner edge
of the second chordal seal at least partially defines a radially
inner edge of the second rail.
In a further embodiment of any of the above, a downstream most
point on the first chordal seal is located axially aft of a
downstream most point on the second chordal seal.
In a further embodiment of any of the above, the first radius of
curvature is equal to the second radius of curvature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an example gas turbine engine.
FIG. 2 is a cross-sectional view of a turbine section of the
example gas turbine engine of FIG. 1.
FIG. 3 is a perspective view of an example vane.
FIG. 4 schematically illustrates dimensions of chordal seals.
FIG. 5 illustrates the vane of FIG. 3 in a first orientation.
FIG. 6 illustrates the vane of FIG. 3 in a second orientation.
DETAILED DESCRIPTION
FIG. 1 schematically illustrates a gas turbine engine 20. The gas
turbine engine 20 is disclosed herein as a two-spool turbofan that
generally incorporates a fan section 22, a compressor section 24, a
combustor section 26 and a turbine section 28. The fan section 22
drives air along a bypass flow path B in a bypass duct defined
within a nacelle 15, and also drives air along a core flow path C
for compression and communication into the combustor section 26
then expansion through the turbine section 28. Although depicted as
a two-spool turbofan gas turbine engine in the disclosed
non-limiting embodiment, it should be understood that the concepts
described herein are not limited to use with two-spool turbofans as
the teachings may be applied to other types of turbine engines
including three-spool architectures.
The exemplary engine 20 generally includes a low speed spool 30 and
a high speed spool 32 mounted for rotation about an engine central
longitudinal axis A relative to an engine static structure 36 via
several bearing systems 38. It should be understood that various
bearing systems 38 at various locations may alternatively or
additionally be provided, and the location of bearing systems 38
may be varied as appropriate to the application.
The low speed spool 30 generally includes an inner shaft 40 that
interconnects, a first (or low) pressure compressor 44 and a first
(or low) pressure turbine 46. The inner shaft 40 is connected to
the fan 42 through a speed change mechanism, which in exemplary gas
turbine engine 20 is illustrated as a geared architecture 48 to
drive a fan 42 at a lower speed than the low speed spool 30. The
high speed spool 32 includes an outer shaft 50 that interconnects a
second (or high) pressure compressor 52 and a second (or high)
pressure turbine 54. A combustor 56 is arranged in exemplary gas
turbine 20 between the high pressure compressor 52 and the high
pressure turbine 54. A mid-turbine frame 57 of the engine static
structure 36 may be arranged generally between the high pressure
turbine 54 and the low pressure turbine 46. The mid-turbine frame
57 further supports bearing systems 38 in the turbine section 28.
The inner shaft 40 and the outer shaft 50 are concentric and rotate
via bearing systems 38 about the engine central longitudinal axis A
which is collinear with their longitudinal axes.
The core airflow is compressed by the low pressure compressor 44
then the high pressure compressor 52, mixed and burned with fuel in
the combustor 56, then expanded over the high pressure turbine 54
and low pressure turbine 46. The mid-turbine frame 57 includes
airfoils 59 which are in the core airflow path C. The turbines 46,
54 rotationally drive the respective low speed spool 30 and high
speed spool 32 in response to the expansion. It will be appreciated
that each of the positions of the fan section 22, compressor
section 24, combustor section 26, turbine section 28, and fan drive
gear system 48 may be varied. For example, gear system 48 may be
located aft of the low pressure compressor, or aft of the combustor
section 26 or even aft of turbine section 28, and fan 42 may be
positioned forward or aft of the location of gear system 48.
The engine 20 in one example is a high-bypass geared aircraft
engine. In a further example, the engine 20 bypass ratio is greater
than about six (6), with an example embodiment being greater than
about ten (10), the geared architecture 48 is an epicyclic gear
train, such as a planetary gear system or other gear system, with a
gear reduction ratio of greater than about 2.3 and the low pressure
turbine 46 has a pressure ratio that is greater than about five. In
one disclosed embodiment, the engine 20 bypass ratio is greater
than about ten (10:1), the fan diameter is significantly larger
than that of the low pressure compressor 44, and the low pressure
turbine 46 has a pressure ratio that is greater than about five
5:1. Low pressure turbine 46 pressure ratio is pressure measured
prior to inlet of low pressure turbine 46 as related to the
pressure at the outlet of the low pressure turbine 46 prior to an
exhaust nozzle. The geared architecture 48 may be an epicycle gear
train, such as a planetary gear system or other gear system, with a
gear reduction ratio of greater than about 2.3:1 and less than
about 5:1. It should be understood, however, that the above
parameters are only exemplary of one embodiment of a geared
architecture engine and that the present invention is applicable to
other gas turbine engines including direct drive turbofans.
A significant amount of thrust is provided by the bypass flow B due
to the high bypass ratio. The fan section 22 of the engine 20 is
designed for a particular flight condition--typically cruise at
about 0.8 Mach and about 35,000 feet (10,668 meters). The flight
condition of 0.8 Mach and 35,000 ft (10,668 meters), with the
engine at its best fuel consumption--also known as "bucket cruise
Thrust Specific Fuel Consumption (`TSFC`)"--is the industry
standard parameter of lbm of fuel being burned divided by lbf of
thrust the engine produces at that minimum point. "Low fan pressure
ratio" is the pressure ratio across the fan blade alone, without a
Fan Exit Guide Vane ("FEGV") system. The low fan pressure ratio as
disclosed herein according to one non-limiting embodiment is less
than about 1.45. "Low corrected fan tip speed" is the actual fan
tip speed in ft/sec divided by an industry standard temperature
correction of [(Tram.degree. R)/(518.7.degree. R)].sup.0.5. The
"Low corrected fan tip speed" as disclosed herein according to one
non-limiting embodiment is less than about 1150 ft/second (350.5
meters/second).
FIG. 2 illustrates an enlarged schematic view of the high pressure
turbine 54, however, other sections of the gas turbine engine 20
could benefit from this disclosure. In the illustrated example, the
high pressure turbine 54 includes a one-stage turbine section with
a first rotor assembly 60. In another example, the high pressure
turbine 54 could include a two-stage high pressure turbine
section.
The first rotor assembly 60 includes a first array of rotor blades
62 circumferentially spaced around a first disk 72. Each of the
first array of rotor blades 62 includes a first root portion 64, a
first platform 66, and a first airfoil 68. Each of the first root
portions 64 is received within a respective first rim 70 of the
first disk 72. The first airfoil 68 extends radially outward toward
a first blade outer air seal (BOAS) assembly 74.
The first array of rotor blades 62 are disposed in the core flow
path that is pressurized in the compressor section 24 then heated
to a working temperature in the combustor section 26. The first
platform 66 separates a gas path side inclusive of the first
airfoils 68 and a non-gas path side inclusive of the first root
portion 64.
An array of vanes 80 are located axially upstream of the first
array of rotor blades 62. Each of the array of vanes 80 include at
least one airfoil 82 that extends between a respective vane inner
platform 84 and a vane outer platform 86. In another example, each
of the array of vanes 80 include at least two airfoils 82 forming a
vane doublet. The vane outer platform 86 of the vane 80 may at
least partially engage the BOAS 74.
As shown in FIGS. 2-4, the vane 80 includes an outer chordal seal
90 and an inner chordal seal 92 located on a respective outer rail
98 and inner rail 110. The outer chordal seal 90 creates a seal
between the vane 80 and the BOAS 74 and the inner chordal seal 92
creates a seal between the vane 80 and a portion of the static
structure 36. In this disclosure, radial or radially and axial or
axially extending is in relation to the axis A of the gas turbine
engine 20.
In the illustrated example, the outer chordal seal 90 extends in a
chordal direction along an axially aft facing surface 94 on the
outer rail 98. The outer rail 98 is located adjacent an aft portion
of the vane 80 and extends radially outward from the vane outer
platform 86. The outer chordal seal 90 extends linearly between
circumferential sides of the outer rail 98.
The outer chordal seal 90 includes an axially downstream facing
surface 100 that includes a radius of curvature RE The surface 100
is spaced from a radially outer edge 102 of the outer rail 98 by a
first plateau 104A. The first plateau 104A is a flat surface having
a radius of curvature approaching infinity. A second plateau 104B
is located radially inward from the surface 100 and spaces the
outer chordal seal 90 from the radially outer platform 86. The
second plateau 104B is also a flat surface having a radius of
curvature approaching infinity.
In the illustrated example, the surface 100 is connected to the
first plateau 104A with a first fillet 105A and the surface 100 is
connected to the second plateau 104B with a second fillet 105B. A
center or downstream most point of the surface 100 on the outer
chordal seal 90 is spaced an axial distance D1 from the first
plateau 104A and an axial distance D4 from the second plateau 104B.
The distance D4 is greater than the distance D1 such that the
second plateau 104B is axially upstream of the first plateau 104A
to allow for greater rotation of the vane 80 without contacting the
blade outer air seal 74. The outer chordal seal 90 is also linear
such that it does not follow a curvature of the radially outer edge
102.
The inner chordal seal 92 creates a seal between the vane 80 and a
portion of the static structure 36. The inner chordal seal 92
extends in a chordal direction along an axially aft facing surface
108 of the inner rail 110. The inner rail 110 is located adjacent
an aft portion of the vane 80 and extends radially inward from the
vane inner platform 84. The inner chordal seal 92 extends linearly
between opposing circumferential sides of the inner rail 110.
In the illustrated example, the portion of the static structure 36
creating the seal with the inner chordal seal 92 is a flange 112 on
a tangent on board injector (TOBI). However, another portion of the
static structure 36 could be used to engage the inner chordal seal
92. The inner chordal seal 92 includes an axially downstream facing
surface 114 that includes a radius of curvature R2. In one example,
the radius of curvature R1 is equal to the radius of curvature R2
and in another example, the radius of curvature R1 is different
from the radius of curvature R2. The variation of radius of
curvature between R1 and R2 can accommodate variations in rotation
of the vane 80 during operation of the gas turbine engine 20 as
will be discussed further below.
The surface 114 is spaced from the inner platform 84 by an outer
plateau 116 on the axially aft facing surface 108 of the inner rail
110. The outer plateau 116 is a flat surface having a radius of
curvature approaching infinity. A center or downstream most point
of the surface 114 on the chordal seal 92 is spaced an axial
distance D2 from the outer plateau 116. The center or downstream
most point on the surface 114 is spaced a distance D3 axially
upstream of the center or downstream most point on the surface 100.
The axially facing surface 114 is truncated by a radially inner
edge 118 of the inner rail 110. The radially inner edge 118 at
least partially defines a radially innermost surface 120 on the
inner rail 110. Because the axially facing surface 114 of the inner
chordal seal 92 is truncated by radially inner edge 118, the
surface 114 at the radially inner edge 118 is axially downstream of
the surface 114 at the outer plateau 116. Additionally, the surface
114 can be connected to the outer plateau 116 by a fillet 117.
During operation of the gas turbine engine 20, the inner rail 110
can shift axially relative to the outer rail 98 as shown in FIGS. 5
and 6. Because the inner chordal seal 92 and the outer chordal seal
90 each include a radius of curvature, the outer and inner chordal
seals 90, 92 roll and maintain a line of contact on the blade outer
air seal 74 and the portion of the static structure 36. Because
inner chordal seal 92 includes a radius of curvature that is
truncated at the radially inner end of the inner rail 110, the
inner rail 110 is able to rotate more without contacting an
additional structure in the gas turbine engine 20 that would break
the seal between the surface 114 and a portion of the engine static
structure 36. Additionally, truncating the radius of curvature R2
on the inner chordal seal 92 reduces extra weight in the vane 80
that is not necessary to maintain a proper seal with the portion of
the engine static structure 36.
The preceding description is exemplary rather than limiting in
nature. Variations and modifications to the disclosed examples may
become apparent to those skilled in the art that do not necessarily
depart from the essence of this disclosure. The scope of legal
protection given to this disclosure can only be determined by
studying the following claims.
* * * * *